1 COMPUTATION OF NET INCOME PER SHARE EXHIBIT 11 Quaker State Corporation and Subsidiaries Quarter Ended Nine Months Ended 9/30/97 9/30/96 9/30/97 9/30/96 - ------------------------------------------------------------------------------------------------------------------------- (in thousands except per share data, unaudited) 1. Net income $ 5,309 $ 6,754 $ 21,018 $ 19,633 ========================================================================================================================= 2. Average number of shares of capital stock outstanding 35,140 35,842 35,042 33,848 3. Shares issuable upon exercise of dilutive stock options outstanding during the period, based on average market prices 313 225 214 154 4. Shares issuable upon exercise of dilutive stock options outstanding during the period, based on higher of average or period-end market prices 517 353 327 346 5. Average number of capital and capital equivalent shares outstanding (2 + 3) 35,453 36,067 35,256 34,002 6. Average number of capital shares outstanding, assuming full dilution (2 + 4) 35,657 36,195 35,369 34,194 7. Net income per capital and capital equivalent share (1 divided by 5) $ 0.15 $ 0.19 $ 0.60 $ 0.58 ========================================================================================================================= 8. Net income per capital share assuming full dilution (1 divided by 6) $ 0.15 $ 0.19 $ 0.59 $ 0.57 =========================================================================================================================